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| author | Zoltan Kiss <zoltan.kiss@citrix.com> | 2013-09-05 00:11:05 +0400 |
|---|---|---|
| committer | Konrad Rzeszutek Wilk <konrad.wilk@oracle.com> | 2013-10-02 20:53:26 +0400 |
| commit | 2b2b614dd24e4e6474fcf2dcf69c95c908838959 (patch) | |
| tree | 9874899c477d237e1ec207834fc730c1151088f5 /include/trace | |
| parent | 04b772d2b819f0dda2163e3193fa7cd447a6245c (diff) | |
| download | linux-2b2b614dd24e4e6474fcf2dcf69c95c908838959.tar.xz | |
tracing/events: Add bounce tracing to swiotbl
Ftrace is currently not able to detect when SWIOTLB has to do double buffering.
Under Xen you can only see it indirectly in function_graph, when
xen_swiotlb_map_page() doesn't stop after range_straddles_page_boundary(), but
calls spinlock functions, memcpy() and xen_phys_to_bus() as well. This patch
introduces the swiotlb:swiotlb_bounced event, which also prints out the
following informations to help you find out why bouncing happened:
dev_name: 0000:08:00.0 dma_mask=ffffffffffffffff dev_addr=9149f000 size=32768
swiotlb_force=0
If you use Xen, and (dev_addr + size + 1) > dma_mask, the buffer is out of the
device's DMA range. If swiotlb_force == 1, you should really change the kernel
parameters. Otherwise, the buffer is not contiguous in mfn space.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
[v1: Don't print 'swiotlb_force=X', just print swiotlb_force if it is enabled]
Signed-off-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Diffstat (limited to 'include/trace')
| -rw-r--r-- | include/trace/events/swiotlb.h | 46 |
1 files changed, 46 insertions, 0 deletions
diff --git a/include/trace/events/swiotlb.h b/include/trace/events/swiotlb.h new file mode 100644 index 000000000000..7ea4c5e7c448 --- /dev/null +++ b/include/trace/events/swiotlb.h @@ -0,0 +1,46 @@ +#undef TRACE_SYSTEM +#define TRACE_SYSTEM swiotlb + +#if !defined(_TRACE_SWIOTLB_H) || defined(TRACE_HEADER_MULTI_READ) +#define _TRACE_SWIOTLB_H + +#include <linux/tracepoint.h> + +TRACE_EVENT(swiotlb_bounced, + + TP_PROTO(struct device *dev, + dma_addr_t dev_addr, + size_t size, + int swiotlb_force), + + TP_ARGS(dev, dev_addr, size, swiotlb_force), + + TP_STRUCT__entry( + __string( dev_name, dev_name(dev) ) + __field( u64, dma_mask ) + __field( dma_addr_t, dev_addr ) + __field( size_t, size ) + __field( int, swiotlb_force ) + ), + + TP_fast_assign( + __assign_str(dev_name, dev_name(dev)); + __entry->dma_mask = (dev->dma_mask ? *dev->dma_mask : 0); + __entry->dev_addr = dev_addr; + __entry->size = size; + __entry->swiotlb_force = swiotlb_force; + ), + + TP_printk("dev_name: %s dma_mask=%llx dev_addr=%llx " + "size=%zu %s", + __get_str(dev_name), + __entry->dma_mask, + (unsigned long long)__entry->dev_addr, + __entry->size, + __entry->swiotlb_force ? "swiotlb_force" : "" ) +); + +#endif /* _TRACE_SWIOTLB_H */ + +/* This part must be outside protection */ +#include <trace/define_trace.h> |